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Background High power shorter duration (HPSD) ablation seen to increase efficacy and safety treating of atrial fibrillation (AF); however, comparative data between HPSD and low power longer duration (LPLD) ablation are limited. Hypothesis We thought that HPSD might bring more clinical benefits. The aim of this meta‐analysis was to evaluate the clinical benefits of HPSD in patients with AF. Methods The Medline, PubMed, Embase, and the Cochrane Library databases were searched for studies comparing HPSD and LPLD ablation. Results Ten trials with 2467 patients were included in the analysis. Pooled analyses demonstrated that HPSD showed a benefit of first‐pass pulmonary vein isolation (PVI) (risk ratio [RR]: 1.20; 95% confidence interval [CI]: 1.10‐1.31, P < .001) and recurrence of atrial arrhythmias (RR: 0.73; 95% CI: 0.58‐0.91, P = .005). Additionally, HPSD could reduce procedural time (weighted mean difference [WMD]: −42.93; 95% CI, −58.10 to −27.75, P < .001), ablation time (WMD: −21.01; 95% CI: −24.55 to −17.47, P < .001), and fluoroscopy time (WMD: −4.11; 95% CI: −6.78 to −1.45, P < .001). Moreover, major complications and esophageal thermal injury (ETI) were similar between two groups (RR: 0.75; 95% CI: 0.44‐1.30, P = .31) and (RR: 0.57; 95% CI: 0.21‐1.51, P = .26). Conclusions HPSD was safe and efficient for treating AF. Compared with LPLD, HPSD was associated with advantages of procedural features, higher first‐pass PVI and reducing recurrence of atrial arrhythmias. Moreover, major complications and ETI were similar between two groups.

Background Although pulmonary vein isolation (PVI) for atrial fibrillation (AF) utilizing radiofrequency (RF) applications with a very high‐power and short‐duration (vHPSD) has shortened the procedure time, the determinants of pulmonary vein (PV) gaps in the first‐pass PVI and acute PV reconnections are unclear. Methods An extensive encircling PVI was performed with the QDOT MICRO catheter with a vHPSD (90 W–4 s) in 30 patients with AF (19 men, 64 ± 10 years). The association of the PV gap sites (first‐pass PVI failure, acute PV reconnections [spontaneous reconnections or dormant conduction provoked by adenosine triphosphate] or both) with the left atrial (LA) wall thickness and LA bipolar voltage on the PVI line and ablation‐related parameters were assessed. Results PV gaps were observed in 29 (6%) of 480 segments (16 segments per patient) in 17 patients (56%). The PV gaps were associated with the LA wall thickness, bipolar voltage, and the number of RF points (LA wall thickness, 2.5 ± 0.5 vs. 1.9 ± 0.4 mm, p < .001; bipolar voltage, 2.59 ± 1.62 vs. 1.34 ± 1.14 mV, p < .001; RF points, 6 ± 2 vs. 4 ± 2, p = .008) but were not with the other ablation‐related parameters. Receiver operating characteristic curves yielded that an LA wall thickness ≥2.3 mm and bipolar voltage ≥2.40 mV were determinants of PV gaps with an area under the curve of 0.82 and 0.73, respectively. Conclusions The LA voltage and wall thickness on the PV‐encircling ablation line were highly associated with PV gaps using the 90 W/4 s‐vHPSD ablation. The left atrial (LA) voltage and wall thickness on the pulmonary vein (PV)‐encircling ablation line were highly associated with PV gaps when using the 90 W/4 s‐vHPSD ablation. The determined cut‐off values for predicting PV gaps were 2.40 mV for LA voltage and 2.3 mm for wall thickness, respectively. These findings provide valuable clinical insights into enhancing first‐pass PV isolation with the 90 W/4 s‐vHPSD ablation technique.

Background High‐power short‐duration (HPSD) ablation is an established therapy for pulmonary vein (PV) isolation (PVI) in atrial fibrillation (AF), aiming to form efficient transmural lesions. Very HPSD (vHPSD) can further shorten ablation time but may increase the risk of acute PVI failure compared with HPSD. A combined HPSD and vHPSD strategy (90 W/50 W combination workflow) potentially balances efficiency and durability, though its clinical feasibility remains unknown. Therefore, this multicenter registry evaluated the acute and long‐term efficacy of a 90 W/50 W combination workflow for PVI in patients with paroxysmal AF. Methods In this prospective study, a total of 101 consecutive patients with paroxysmal AF underwent PVI using radiofrequency ablation with a 90 W/50 W combination workflow. We evaluated acute outcomes, including first‐pass isolation and acute PV reconnection, and monitored atrial tachyarrhythmia recurrences over 12 months. Results Median PVI procedure time was 35 min, with total procedure time at 105 min. First‐pass PVI was achieved in 58.4% of patients, including 74.3% in the right PV and 72.3% in the left PV. Acute PV reconnection occurred in 31.7% (32/101). In multivariate analysis, carina sites independently predicted acute PVI failure in both HPSD and vHPSD groups, while contact force also predicted failure in the HPSD group. After 1 year, 89.9% of patients remained free from documented atrial tachyarrhythmias. Conclusion The 90 W/50 W combination workflow did not notably shorten procedure time or enhance first‐pass success. More standardized strategies, particularly in carina segments with higher contact force and ablation index under HPSD, may be required to ensure optimal lesion durability and favorable outcomes. This multicenter registry evaluated a 90 W/50 W combination workflow for pulmonary vein isolation (PVI) in 101 patients with paroxysmal atrial fibrillation. First‐pass PVI was achieved in 74.3% of right and 72.3% of left PVs. The 1‐year atrial tachyarrhythmia recurrence‐free survival was favorable at 89.9%, suggesting this strategy is a clinically effective option for achieving durable PVI.

Introduction A novel temperature‐controlled radiofrequency (RF) catheter enables pulmonary vein isolation (PVI) using very high‐power short‐duration (vHPSD) ablation, reducing esophageal injury risk but raising concerns about lesion durability in thicker atrial myocardium. This study aimed to assess the efficacy and safety of a hybrid approach that integrates conventional Ablation Index (AI)‐guided PVI with vHPSD ablation. Methods This prospective, single‐center study enrolled 160 consecutive patients with atrial fibrillation (AF) between January 2023 and December 2023, who were allocated into two groups. Group 1 (n = 80) underwent conventional AI‐guided PVI using a 40 W setting, while Group 2 (n = 80) received a hybrid approach combining 90 and 50 W ablation with a temperature‐controlled RF catheter (QDOT Micro, Biosense Webster Inc., Diamond Bar, CA). Results Group 2 demonstrated a significantly shorter duration for PVI compared to Group 1 (28 ± 11 min vs. 35 ± 10 min, p < 0.001), with similar rates of first pass isolation (86% vs. 89%, p = 0.63) and acute reconnection (10% vs. 5%, p = 0.23). Complication rates were comparable between the groups (1.3% vs. 1.3%, p = 1.00), with no cases of esophageal or phrenic nerve injury reported. Kaplan–Meier analysis showed no significant difference in freedom from AF at 1 year (84% vs. 83%, log‐rank p = 0.78). Conclusion The integration of Ablation Index‐guided ablation with vHPSD ablation, utilizing a novel temperature‐controlled RF catheter, significantly reduces procedural duration while maintaining safety and efficacy comparable to conventional AI‐guided PVI. Compared to conventional Ablation Index (AI)‐guided ablation, the hybrid AI + very high‐power short‐duration (vHPSD) strategy significantly reduced pulmonary vein isolation time (28 ± 11 vs. 35 ± 10 min, p < 0.001), with comparable first‐pass isolation (86% vs. 89%, p = 0.63), acute reconnection (10% vs. 5%, p = 0.23), complication rates (1.3% vs. 1.3%), and 1‐year arrhythmia‐free survival (84% vs. 83%, log‐rank p = 0.78).

Background The efficacy and safety of tailored pulmonary vein isolation (PVI) guided by either left atrial wall thickness (LAWT) or bipolar voltage remain unclear. Objective The aim of this prospective study was to evaluate the efficacy and safety of each ablation strategy. Methods We conducted a prospective analysis of 97 patients with non‐valvular atrial fibrillation (AF) who underwent an initial RF catheter ablation procedure known as an extensive encircling PVI. Fifty patients underwent PVI using a wall thickness (WT)‐guided approach using ADAS 3D software and 47 patients using a voltage‐guided approach. In each strategy, high‐power short‐duration (HPSD) ablation was applied to regions with increased LAWT or elevated bipolar voltage, respectively, while very high‐power short‐duration (vHPSD) ablation was delivered to the remaining regions. Results The first‐pass PVI rate tended to be higher in the WT‐guided group compared to the Voltage‐guided group (43 [86%] vs. 34 [72%], p = 0.09), and the incidence of acute PV reconnection (APVR) tended to be lower (5 [10%] vs. 11 [23%], p = 0.07). The proportion of patients with PV gaps (defined as the combined occurrence of first‐pass failure and/or APVR) was significantly lower in the WT‐guided group (10 [20%] vs. 18 [38%], p = 0.04). The multivariable‐adjusted analysis demonstrated that WT‐guided ablation was significantly more effective than Voltage‐guided ablation in preventing PV gaps. Both ablation strategies were performed without any procedural complications. Conclusions WT‐guided ablation was associated with a significantly lower incidence of PV gaps than a conventional bipolar voltage‐guided strategy. Wall‐thickness guided pulmonary vein isolation using integrated pre‐procedural CT imaging and ADAS 3D software was associated with a significantly lower incidence of PV gaps than a conventional bipolar voltage‐guided strategy despite similar 1‐year clinical outcomes. These findings support individualized, left atrial wall thickness–based strategies in the high‐power RF ablation era.

Background Very high‐power short‐duration (vHPSD) ablation with the novel QDOT™ catheter allows the regulation of target temperature by automatically adjusting flow and power during a 4 s application of 90 W. However, the optimal contact force for sufficient lesion creation is unknown. Methods We enrolled 73 patients with symptomatic atrial fibrillation undergoing pulmonary vein isolation (PVI) using the QDOT catheter in the vHPSD mode (90 W, 4 s). Ablation metrics associated with suboptimal applications, defined as either an impedance drop of ≤5% or a cumulative temperature‐limited energy ≤330 J, were collected and analyzed. Results A total of 3881 vHPSD applications (53.2 applications per patient) with a mean contact force (CF) of 12.8 ± 6.6 g were analyzed. Significant CF variability and intermittent loss of contact were documented in 18.2% and 8.8% of the applications, respectively. A ΔImp ≤ 5% occurred in 3.9% of vHPSD applications, while a cumulative energy ≤ 330 J was observed in 3% of the applications. Applications with a mean CF < 6 g and >22 g were associated with an inadequate impedance drop (10.3%, Phi coefficient 0.118, p < .001) and total applied energy (7.8%, Phi coefficient 0.094, p < .001) respectively. At superior PV segments with thick atrial walls, significantly more applications with cumulative energy ≤330 J (4.2% vs. 2.5%; p = .007) were observed, especially when mean CF > 18 g was applied (8.4%, Phi coefficient 0.093, p = .003). Conclusion A lower but also a higher mean contact‐force was associated with suboptimal vHPSD applications. Hence, a “16‐gram window” of contact‐force, from 6 to 22 g, could optimize energy application in vHPSD ablation. A lower but also a higher mean contact‐force was associated with suboptimal vHPSD applications. Hence, a “16‐gram window” of contact‐force, from 6 to 22 g, could optimize energy application in vHPSD ablation.

Background/Objectives Very high‐power and short‐duration (vHPSD) ablation with QDOT MICRO™ facilitates speedy and safe ablation for pulmonary vein isolation. A brief time interval between ablating two neighboring sites with vHPSD may potentially influence the size and geometry of the lesions. This study evaluates lesion formation when delivering adjacent applications using vHPSD at various inter‐lesion times (ILTs). Methods Radiofrequency applications were conducted by QDOT MICRO™ catheter with 90 W of strength and 4 s duration. Fresh swine heart tissue on the epicardium was ablated with 10 g of the contact force. Lesions were created using a single application (SA) and double applications (DA) of adjacent lesions with a 6 mm distance between them as measured on the 3D mapping system. The DA was performed with various ILTs, 60 s (DA‐60 s), 10 s (DA‐10 s), 5 s (DA‐5 s), and 0 s (DA‐0 s). Results Out of 90 lesions, 79 were analyzed. Eleven lesions were excluded for one steam pop event, seven out of the target distance, and three divided lesions of two applications. There were no significant differences in surface diameter, cross‐sectional diameter, and maximal lesion depth in each application among the groups. The intermediate lesion depth was significantly more profound in groups with shorter and immediate ILT (DA‐10, 5, and 0 s) compared to the group with a prolonged ILT between two applications (DA‐60 s) (2.99, 3.03, 3.16 mm vs. 2.42 mm, respectively; p < .001). Conclusions Two adjacent radiofrequency applications with vHPSD in short ILT may result in deeper lesions in the middle of combined double lesions. Radiofrequency lesions were created using double applications (DA) with a 6 mm inter‐lesion distance (ILD) and inter‐lesion times (ILT) of 60, 10, 5, and 0 s. Shorter ILT groups (10, 5, 0 s) showed significantly deeper intermediate lesion depth than the 60 s group, suggesting involvement of the conductive thermal effect.

Background Lesion size is reported to become larger as contact force (CF) increases. However, this has not been systematically evaluated in temperature‐guided very high‐power short‐duration (vHPSD) ablation, which was therefore the purpose of this study. Methods Radiofrequency applications (90 W/4 s, temperature‐control mode) were performed in excised porcine myocardium with four different CFs of 5, 15, 25, and 35 g using QDOT‐MICRO™ catheter. Ten lesions for each combination of settings were created, and lesion metrics and steam‐pops were compared. Results A total of 320 lesions were analyzed. Lesion depth, surface area, and volume were smallest for CF of 5 g than for 15, 25, and 35 g (depth: 2.7 mm vs. 2.9 mm, 3.0 mm, 3.15 mm, p < .01; surface area: 38.4 mm2 vs. 41.8 mm2, 43.3 mm2, 41.5 mm2, p < .05; volume: 98.2 mm3 vs. 133.3 mm3, 129.4 mm3, 126.8 mm3, p < .01 for all pairs of groups compared to CF = 5 g). However, no significant differences were observed between CFs of 15–35 g. Average power was highest for CF of 5 g, followed by 15, 25, and 35 g (83.2 W vs. 82.1 W vs. 77.1 W vs. 66.1 W, p < .01 for all pairs), reflecting the higher incidence of temperature‐guided power titration with greater CFs (5 g:8.8% vs. 15 g:52.5% vs. 25 g:77.5% vs. 35 g:91.2%, p < .01 for all pairs except for 25 g vs. 35 g). The incidence of steam‐pops did not significantly differ between four groups (5 g:3.8% vs. 15 g:10% vs. 25 g:6.2% vs. 35 g:2.5%, not significant for all pairs). Conclusions For vHPSD ablation, lesion size does not become large once the CF reaches 15 g, and the risk of steam‐pops may be mitigated through power titration even in high CFs. This study demonstrates the effect of CF on 90 W/4 s ablation using QDOT‐MICRO catheter. Lesion sizes do not become larger once CF reaches 15 g. Steam‐pops do not increase with CF owing to the effective power titration with temperature limit.

Background We explore an optimized approach for increasing lesion size using a novel ablation catheter with a surface thermocouple and efficient irrigation in a temperature‐control setting. Methods We conducted radiofrequency applications at various power levels (35 W, 40 W, and 45 W), contact forces (CFs, 10 g/20 g), and durations (60 s/120 s/180 s) in perpendicular/parallel catheter orientations, with normal saline irrigation (NS‐irrigation) and Half NS‐irrigation (HNS‐irrigation) in an ex‐vivo model (Step 1). In addition, we performed applications (35 W/40 W/45 W for 60 s/120 s/180 s in NS‐irrigation and 35 W/40 W for 60 s/120 s/180 s in HNS‐irrigation) in four swine (Step 2), evaluating lesion characteristics and the occurrence of steam pops. Results In Step 1, out of 288 lesions, we observed 47 (16.3%) steam pops, with 13 in NS‐irrigation and 34 in HNS‐irrigation (p = .001). Although steam pops were mostly observed with the most aggressive setting (45 W/180 s, 54%) with NS‐irrigation, they happened in less aggressive settings with HNS irrigation. Lesion size significantly increased with longer‐duration ablation but not with HNS‐irrigation. The optimal %impedance‐drop cutoff to predict steam pops was 20% with a negative‐predictive‐value (NPV) = 95.1% including NS‐ and HNS‐irrigation groups, and 22% with an NPV = 96.1% in NS‐irrigation group. In Step 2, similar to the ex‐vivo model, lesion size significantly increased with longer‐duration ablation but not with HNS‐irrigation. Steam pops were absent with NS‐irrigation (0/35) even with the largest %impedance‐drop reaching 31% at 45 W/180 s. All steam pops were observed with HNS‐irrigation (6/21, 29%). The optimal %impedance‐drop cutoff predicting steam pops was 24% with an NPV = 96.3% including both NS‐ and HNS‐irrigation groups. Conclusions Rather than using HNS‐irrigation, very long‐duration of radiofrequency applications up to 45 W/180 s may be recommended to safely and effectively increase lesion dimensions using this catheter with NS‐irrigation. In both ex‐vivo and in‐vivo studies, the radiofrequency application in a temperature‐controlled setting using a catheter equipped with a surface thermocouple and efficient irrigation demonstrates an increase in lesion size as the ablation duration extends up to 180 s. However, the utilization of half‐normal saline irrigation may not lead to a proportional increase in lesion size, but with more frequent steam‐pops.

Background The efficiency of pulmonary vein isolation (PVI) depends on the durability of RF lesions. Recent studies documented sustained continuity of ablation lines, improvements in durability, and expected clinical outcomes through altered settings in duration and power. However, the ablation strategy has not been adapted to this new approach and different biophysics of lesion formation. Purpose The aim of this study was to demonstrate that by adjusting the ablation approach to the broader geometry of lesions by increasing the minimal spacing between adjacent RF, a further significant reduction of procedural time while maintaining sufficient long‐term outcomes is achievable. Methods The presented study was a prospective, observational multi‐center trial. The periprocedural data were compared with data from a consecutively collected historical cohort. Results In total, 196 patients were included (mean age 62 ± 11 years, male 64.3%). Procedural duration, RF time, and LA dwelling time were significantly shorter in the HPSD group compared with the standard group (73 ± 26 min vs. 98 ± 36 min, p < .001; 14 ± 7 min vs. 33 ± 12 min, p < .001; and 59 ± 21 min vs. 77 ± 32 min, p < .001, respectively). Mean AF‐free survival in the first year of follow‐up was 304 ± 14 days in the HPSD group versus 340 ± 10 days in the standard group (log‐rank p = .403). There were no statistically significant differences in the complication rates between the groups. Conclusion Increasing the minimal distance between individual application points simplifies AF ablation and further reduces procedure time without negative effects on efficacy and safety. Larger studies are needed to optimally utilize this approach. This unique work focusing on a novel protocol for optimal utilization of HPSD approach usage in PVI will be a fundament of setting up a simplified and reduced procedure time HPSD approach usage in PVI.